General Petraeus affair details emerge

In this August 31, 2011 file photo, former Commander of International Security Assistance Force and US Forces-Afghanistan General Davis Petraeus, standing with his wife Holly.

Further details have emerged about the resignation of the CIA's director. The FBI, which had been investigating David Petraeus, appears to have been tipped off by a family friend that he was having an extra-marital affair. Al Jazeera's Rob Reynolds explains.